In recent years, removal of harmful substances such as free residual chlorine from drinking water has been desired. Further, since there are still many cases in which lead-containing materials are used for water pipes, there is demand for a water cleaner that has an excellent ability of removing heavy metal ions.
As an activated charcoal for removing heavy metals, for example, Japanese Patent Application Laid-Open (JP-A) No. 2003-334543 discloses a molded activated charcoal that is produced by molding a mixture of fiber-shaped activated charcoal, microparticles of an inorganic compound that has an ability of adsorbing heavy metals and has a particle size of from 0.1 μm to 90 μm, and a binder. In the molded activated charcoal, an aluminosilicate zeolite is used as the inorganic compound.
With regard to removal of heavy metal compounds that are included in general industrial wastes, waste products generated in a solvent production process, waste products generated in a synthetic rubber production process, laboratory wastes, medical wastes or household wastes, for example, JP-A No. 2000-342962 discloses a heavy metal adsorbent that is produced by bonding a compound having a chelate-forming group to a porous substance that is at least one selected from the group consisting of activated charcoal, zeolite, diatomite, natural sand and ceramics.